Elevator safety device.



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I. P. DRAWBAUGH.

ELEVATOR SAFETY DEVICE.

APPLICATION FILED MAY 24. 1913.

Patented Jan. 18, 1916.

2 SHEETS-SHEET I.

awuzwtoz Mc THE COLUMBIA PLANOGRAPH 60., WASHINGTON. n. C

I. P. DRAWBAUGH.

ELEVATOR SAFETY DEVICE. APPLICATION FILED MAY 24,1913.

1 1 69,0 15 Patented Jan. 18, 1916.

2 SHEETS-SHEET 2- Am a?) THE COLUMBIA PLANoGRAPu 50., WASHINGTON. D. C-

MICE-1 ISAAC r; DRAWBAUGH, or us QUEEN, ARKANSAS.

ntnva'ron' SAFETY DEVICE.

To all whom it may come 2%.

Be it known that I, ISAAC P. DnAwBxUoI-r, citizen of the UnitedStates,residing at De Queen, State of Arkansas, have. invented certainnew and. useful Improvements in Elevator Safety Devices, of which thefollowing is a specification.

, This invention relates to an improved apparatus to be used as anemergency brake for the car or cage of an elevator shaft.

The primary object of the invention is to provide simple and inexpensivemeans for positively and automatically stopping the elevator car or cageshould the lifting cable become broken or the operating mechanismderanged.

A furtherobject of the invention resides in the provision of pneumaticmeans arranged upon the top of the car or cageto act as a cushiontherefor, this arrangement absorbing the shock and jolt that wouldotherwise be manifest were the said means not provided.

The invention still further resides in the provision of a safetyattachment for elevators which may be applied to the cars or cages ofthe ordinary construction without altering or changing the car to anymaterial extent. I

The above and additional objects are ac complished by such means as areillustrated in their preferred embodiment in the accompanying drawings,described in the following specification and then more particularlypointed out in the claims which are appended hereto and form a part ofthis application.

In describing my invention in detail reference will be had to theaccompanying drawings, wherein like characters denote like orcorresponding parts throughout the several views, and in which Figure 1isa side elevation, one of the compressed air cylinders being shown insection of a device constructed in accordance with my invention, the caror cage of the elevator being broken away; Fig. 2 is a top plan view ofthe brake operating mechanism, the elevator guides being shownin'section; Fig. 3 is a.

section on line 33 of F ig.*2; Fig. alis an end view illustrating thearrangement of the brake shoes; Fig. 5 is a detail perspective view ofone of the brake shoes; and Fig. 6 is an enlarged section on line 66 ofFig. 2.

Referring now to the drawings, wherein is illustrated the preferred formof my invention the numeral 1 designates the elevator I Specification ofLetters Patent. "Patented Jan. 18, 1916, Application filed May 24, 1912.Serial No. 769,670. i

cage or .car to which is secured in any suitable manner a pair ofvertically extending cylinders 2, the said cylinders being disposed uponthe top of the car or cage, one near each side thereof, and providedwith a pistonrod 3 havinga piston l secured to its lower extremitywithin the cylinder 2. The rods 3 are secured to a. suitable metalliccasing 5 through the medium of nuts 6. arranged over the upperextremities of the said rods, the

latter projecting from the cylinders at the p top thereof and extendingthrough the casing 5 as is clearly shown in Fig. 1 of the drawings. Theusual guide beams 6 are positioned one upon each side of the elevatorcar, the said beams extending throughout the entire length of theelevator shaft for it guiding the elevator during its travel. Cut outportions 7 are formed within the extremities of the casing'5 withinwhich the guide beams 6 are fitted, the said beams adapted tofrictionally engage suitable brake shoes Sdove-tailed as at 9 within thecasing ends 5, one upon each side of the cut out portions 7 formed.therein, the mechanism for operating the said brake shoes to be here.-inafter fully described.

' A shaft 10 extends across the elevator shaft and is journaled withinsuitable bean ings 11, thelatter being adjustably secured as at 12 tothe casing 5 so as to position the extremities of the shaft adjacent theguide beams 6 of the elevator mechanism. Rollers or friction wheelsBare-keyed or otherwise secured upon the extremities of the shaft 10 andare adapted to frictionally engage the sides of the guide beams 6 forimparting H rotary movement to the shaft 10 during the travel of theelevator car throughout the length of the shaft. A governor, designatedin its entirety by the numeral 14: is arranged upon the shaft 10 nearone end thereof, the said governor comprising the usual weight members15 pivotally secured to suitable arms 16 in turn pivotally secured to abracket 17 fixedly secured to the shaft 10. A second 7 pair of arms 18are pivotally secured to the weight members 15 and extend to a secondbracket 19 slidably. arranged over the said shaft 10 and normally heldin spaced relation to the stationary bracket 17 through the medium of anexpansion spring 20 ar ranged overthe said shaft, one end of whichengages suitable lock nuts 21 threaded on the saidshaft whileitsopposite end bears against the said slida-ble bracket 19.

- levers 22 are normally supported by the v The means for operating thebrake shoes 8, the said means being controlled by the r0- tation of thegovernofl-l,comp-rises a pair of bell crank levers 22, the saidrleversbeing pivotally secured as at 23 within a cut out p0rt 0n2e Qft c sing5, one near .ea hend "thereof or adjacent the guide beams 6. The saidtwo levers 22 being ina'duplicate butone will be described in detail. Apair of seg- -mentajl raeks= 25 are fonmed integrally withtheiibellnoranlklever 22, thessa'id raeks being arrangedin spacedrelation so was to engage rack bars '26 -for ned upon the brake shoes 8and extendingthroughout the entire length of theinner facethereof. il hesaid racks-25 are normally held in ,mesh with the rack bars-26' throughthe medium ofa t 'i g ger arm 27 broken centrally #as ;at :28 =tosperm-it pivotal movement thereof and :terininative at itslower-extremity in a longitudinally ex- -r0d"29 jonrnaled withinsuitable brackets30 arranged uponthe upper face of the easing 5 andextending to a point above the I said casing adjacent the -said -members -15 0f the governor, the opposite end of the said rod from that ofthe trigger arm 27 being provided with a lever 81 adaptedto be engagedby lugs formed uponthe said :weightlineinbers 15 of-the-gow ernorasthelatter are rapidly revolved in .a manner to "be he-reina fter fully setforth. 'fl he inner or free ends of :the bell crank trigger-arm 27 ofthe trip meehanisnnthis arrangement holding the -racks, 25 inoperativeWith respect to the'rack bars 26 of the brake shoes. Spri-ng's 33 aresecured to each of'the levers 22 for rocking thesaid levers 0r swingingthe same upon their pivot supports '23 when the trigger-arm 27 iswithdrawn from engagement with-the free ends of the said levers, thetension of the springs movingthe racks 25 and lifting :the brake shoes'8 so as to wedge the same betweenthe guide beams '6 andthe extremities:of the casing 5 as is clearlyshown in Fig. Aof-the drawings. 'Toincrease the frictional e11- gagement between the said shoes and theguide *beams 6 the engaging faces of the said shoes 8 are serratedas at34:.

Having described indetail-the construction of the apparatus or device,the 1 opera- 'tion of the same will now=beifully set forth.

Should the supporting cable or rope oft-he elevator car for-any reasonbreak, .orshould the operating mechanism become deranged, theaveightofthe car or cage will c'ausethe same to drop or F fall, 1 this 1movement of the car rapidly rotating the friction rollers 13, in turnimparting a like movement to the shaft 10. 'As the shaft 10 rotatesabnormally fastthe weight members ofetheigovernor 14; expand until thelugs 32 thereof 1 engage the lever 31, such engagement throwing the triparm 27 out (if-engagement with Letters Patent, is

the free ends ofthe operating bell crank levers 22. The free extremitiesofthe bell crank levers being unsupported the tension ofathe springs 33will swing the racks 25 upon their pivotal support, this movement of.theracks elevating the brake shoes ,8 and wedging the same betweenthe-inner faces of the cut .ontiportions 7 and the guide members 6 andthus preventing further movement of the car 1.

To absorb the ShOGlCallGlmIGllBVf-B the strain upon the casing 5themechanism carri-ed thereby, the compressed air cylinders, 2 have beenprovided. As thewbrakes areapplied in the manner above set forth'zthesaid cylinders 2 are free toanovenponthe piston rods :which .arestationary and as the piston t is :clrawn toward the upper extremit ofthe said .scyl'i'nders the =.air contained within the latter iscompressed thereby forming .a cushion for :the car body and preventingserious injury to the occupants thereof.

:It-will be seen fromuthe above, taken in connection with theaccompanyingdrawings that the entire brake mechanism is controlled bythe rotation of thefrictionmb'llers from engagement :wi-thg the :freeends 'of the operating levers .22 and that :the vprovision of 1 thesprings '33, 1 disposedxas 1 they are with respect to the 1 saidoperating levers, -will-operate thesegmental racks 25 and verticallyslidethe -rbnake shoes until :the same become wedged against :theguidebeams 6 0f the elevator mechanism.

In reduction :topracticegI have found that the form of my invention,illustrated in-the drawings'and' referned to in theabove .description,:{LS the preferred embodiment, is the most efiicient and practical; yetrealizing that the conditions concurrent with the adoption .of:my devicewill necessarily vary, I desire to emphasizethe fact that various minorchanges in details of construction, proportion =-andarrangement of partsmay be resorted to, 'when required, without sacrificing any ofwtheadvantages of any invention, as defined in'ithe appended claims.

:HaVing-thus fullydescribed my invention, what Iclainras new;and desireto-secure by 1. An emergency brake for elevator cars including a{plurality of friction rollers, guide beams upon which the rollers ride,rack carrying brake shoes -m0va ble into and out of engagement with saidbeams, and means controllable by movement of said rollers adapted toengage the shoe racks to force the shoes'againstthebeams.

2. An emergency brake for elevator cars including a wedge shapedshoe,'teeth formed upon the shoe, a guide beam extending longitudinallyof the elevator shaft, a segment engaging the teeth of said shoe, meansnor mally maintaining the segment inoperative, means controlled throughmovement of the elevator to actuate said last mentioned means, and meansoperating"automatically to move the shoe in engagement with the beamupon a release of the control means for the segment,

3. An emergency brake for elevator cars including a pair of wedge shapedshoes, guide beams extending longitudinally of the elevator shaft, teethformed upon the respective shoes, a segment engaging the teeth of eachshoe, trip means normally maintaining the segments inoperative, andmeans controlled through movement of the ele vator car to actuate saidtrip means to provide for movement of the respective shoes intoengagement with the respective guide beams, as and for the purpose setforth.

4. An emergency brake for elevator cars including a wedge shaped .shoe,teeth formed upon the said shoe, a guide beam extending longitudinallyof the elevator shaft, a segment engaging the teeth of said shoe, trip 4means normally maintaining the segment inoperative, a friction rollerengaging the said. beam, and means controlled through movement of saidroller to actuate said trip means and provide for movement of said shoein engagement with said beam.

An emergency brake for elevator cars including a pair of wedge shapedshoes, teeth formed upon the respective shoes, guide beams extendinglongitudinally of the elevator shaft, a segment engaging the teeth ofeach shoe, spring actuated levers rigid with the respective segments,trip means engaging the respective levers to hold the latterinoperative, and means controlled through movement of the elevator carto actuate said trip means.

6. An emergency brake for elevator cars including a pair of brake shoes,guide beams extending longitudinally of the elevator shaft, meansengaging said shoes for moving the latter into frictional engagementwith the respective guide beams, trip means normally, holding said lastmentioned means inoperatlve, friction rollers engaging the respectivebeams, and governor mechanism operable through movement of the friction"rollers to actuate said trip means.

7. An emergency brake for elevator cars including a pair of wedge shapedshoes, teeth formed upon the respective shoes, guide beams extendinglongitudinally of the elevator shaft, a segment engaging the respectiveteeth of the said shoes, said seg-- ments being actuatable to move thesaid shoes into frictional engagement with the operate said trip meansand release said levers.

S. An emergency brake for elevator cars including a pair of wedge shapedshoes,

teeth formed upon the respective shoes,

guide beams extending longitudinally of the elevator shaft, a segmentengaging the teeth of each shoe, a lever rigid with each seg ment,spring means engaging the respective lovers to actuate said segments andmove said shoes simultaneously into engagement with the respective beamsthe mo- I ment said levers are released, trip means normally maintainingthe levers inoperative, rollers adapted for frictional engagement withthe respective beams, governor mechanism aetuatable through rotation ofsaid rollers, the said governor mechanism being engageable with saidtrip mechanism when rotated at a predetermined speed to actuate saidmechanism and release said levers to provide for movement of therespective shoes, as and'for the purpose set forth.

In testimony whereof I aflix my signature in presence of two witnesses.

ISAAC P. DRAWBAUGH.

' lVitnesses: I

LomN Green, D. L. Cowman.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. C.

